Azad Yadav, whose gun was used by his son and a friend for allegedly killing their classmate at a school in Gurgaon, was on Friday arrested for negligence in handling the firearm.

The police had lodged a case against Yadav under the Arms Act for negligence in handling the revolver, which was used in the killing of 14-year-old Abhishek Tyagi, a class 8 student of Euro International School, on December 11.

He must not have allowed his child to steal the revolver and take it to school, Deputy Commissioner of Police Satish Balan said.

Meanwhile, police have found that Yadav did not have a license for the weapon.

"He was granted the permission only for a double barrel gun," Commissioner of Police Mohinder Lal said.

Yadav, on the other hand, said the US-make .32 gun belonged to his neighbour.

According to Lal, if this was the case, both Yadav and his neighbour are equally responsible for the lapse.

At least 65 per cent students of Euro International School attended classes on Friday as the institution reopened, chairman Satvir Yadav said.

The school authorities took the services of seven consultants in a bid to remove fear psychosis from the students.

The school started with a two-minute condolence meeting in the memory of Abhishek.

A strong police force was stationed around the school and the media was not allowed to speak to the children or their parents.